Specific Heat of a Metal

A metal container, which has a mass of 9.0 kg contains 17.6 kg of water. A 2.0-kg piece of the same metal, initially at a temperature of 200.0°C, is dropped into the water. The container and the water initially have a temperature of 15.1°C and the final temperature of the entire system is 17.1°C. Calculate the specific heat of the metal.

I used this equation but I still can't seem to get the right answer.....[C(metal)*Mass(container)*deltaT(container)] + [4186*Mass(water)*deltaT(water)] = Cmetal*Mass(peice)*deltaT(piece)